Scalar Higgs boson production in fusion of two off-shell gluons

Abstract

The amplitude for scalar Higgs boson production in a fusion of two off-shell gluons is calculated including finite (not infinite) masses of quarks in the triangle loop. In comparison to the effective Lagrangian approach, we have found a new term in the amplitude. The matrix element found can be used in the k ⊥ -factorization approach to the Higgs boson production. The results are compared with the calculations for on-shell gluons. Small deviations from the cos 2 φ-dependence are predicted. The off-shell effects found are practically negligible.

Inclusive Higgs boson production at the LHC in the kT -factorization approach

“…More detailed descriptions of the k T -factorization formalism can be found, for example, in reviews [54]. The k T -factorization approach has been already applied to the inclusive Higgs boson production [53,[55][56][57][58][59][60][61][62]. So, the effective Lagrangian [54,63] for the Higgs coupling to gluons (valid in the large top quark mass limit, m t → ∞) was used [53,55,[57][58][59][60][61][62] to calculate the amplitude of dominant gluon-gluon fusion subprocess, whereas finite top mass m t effects in the triangle quark loop were investigated [56].…”

Small-x phenomenology at the LHC and beyond: HELL 3.0 and the case of the Higgs cross section

“…We then studied a specific hadron-hadron collider process, namely Higgs production in gluon fusion. The partonic coefficient functions with incoming off-shell gluons needed for obtaining the resummed on-shell coefficient functions for this process have been computed a while ago [64][65][66]. However, it was possible to obtain consistent resummed predictions only thanks to two recent developments.…”

“…The dimensionless form factors A 1 and A 3 have been computed in Refs. [65,66]. Before presenting their form, we observe that numerical integration of this function is problematic in the region ξ 1 ∼ ξ 2 .…”

“…where in the last line we have assumed F to be symmetric, so that the problematic region ξ 1 = ξ 2 lies at the boundary of the integration domain and can be better integrated numerically. In terms of these variables, the form factors [65,66] have a simpler form given by…”

Diffractive exclusive production of Higgs boson and heavy quark pairs at high energy proton-proton collisions

“…The details of the off-shell matrix element can be found in Ref. [7]. In contrast to the exclusive χ c production [8], due to a large factorization scale ∼ M H the off-shell effects for g * g * → H give only a few percents.…”